BILIARY FISTULA (Part one)

Biliary Fistulas
Biliary fistulas are uncommon and are grouped as spontaneously occurring or as iatrogenic, postoperative, or post-traumatic. They are specified also as internal or external by the site of exit of the fistula.
Most spontaneous biliary fistulas result from complications of gallstone disease, frequently when there have been delays in or insufficient treatment of symptomatic disease.

• The most frequent site of fistulization in spontaneous cases is to the gastrointestinal (GI) tract, particularly the duodenum, and passage of a large stone through such a fistula may result in gallstone ileus.
• Rarely, fistulas occur externally to the skin or internally to another part of the biliary tree, to the pleural cavity or bronchial tree, or to the hepatic artery or portal vein or other vascular structures.
  

INTERNAL BILIARY FISTULA
In general, internal biliary fistulas are spontaneously occurring results of biliary tract disease. The major types include biliary-enteric, biliobiliary, bronchobiliary and pleurobiliary, and biliary-vascular fistulas.

Biliary-Enteric Fistula

• The incidence of such fistulas is unknown, but it is low.
• Two thirds of patients with biliary-enteric fistulas have symptoms for 2 years or more.
• Ninety percent of patients with biliary-enteric fistulas have had a history of biliary tract disease for an average of 12 years (range, 1 to 18 years).
• Cholecystoduodenal fistulas constitute 72 to 80% of biliary-enteric fistulas;
• cholecystocolic fistulas make up 8 to 12%;
• cholecystogastric and choledochoduodenal fistulas are almost equal in frequency at 3 to 5%;
• and other bilioenteric fistulas are mostly combination fistulas such as cholecystogastroduodenal or cholecystoduodenocolic and total 2 to 3%.

Gallstones are the primary etiologic agent in most internal biliary-enteric fistulas. Glenn and colleagues proposed the following course:

(1) stone formation in the gallbladder;

(2) acute inflammation with obstruction of the cystic duct that results in adhesions of the gallbladder to the adjacent viscus (usually the duodenum); and

(3) repeated attacks of inflammation inducing gangrene of the gallbladder wall and wall of the adherent viscus, with eventual erosion and fistula formation.

• An alternative mechanism postulates that the fistula is due to direct mechanical pressure of the gallstone on the wall of the containing organ—gallbladder or common bile duct—with erosion and necrosis until a fistula is formed.
• Carcinoma of the gallbladder, bile duct, duodenum, pancreas, or stomach is an infrequent cause of these fistulas.
• Crohn's disease of the duodenum, peptic ulceration into the gallbladder, and paraduodenal abscess have been found as etiologic agents in rare cases.
  

Clinical symptoms and signs are frequently not helpful in diagnosing biliary-enteric fistula.

• Right upper quadrant pain and tenderness are frequently similar to those noted in uncomplicated symptomatic gallbladder disease.
• Jaundice is present at some time in the disease course in over half of patients, and vague right upper quadrant fullness may be present.
• Other symptoms may include fever, chills, nausea, vomiting, bloating, fatty food intolerance, weakness, and backache.
• Cholangitis occurs in approximately 17% of all patients with biliary-enteric fistula but in 60% of those with cholecystocolic fistula and in 40% or more of those with cholecystogastric fistula.
• Gallstone ileus occurs in 13 to 30% of patients with biliary-enteric fistula.
• With cholecystocolic fistula, diarrhea is frequently prominent because of bacterial action on bile salts, and malabsorption may occur.
• An increased incidence of biliary tract carcinoma is associated with biliary-enteric fistulas.
  

Diagnosis has been made preoperatively in 43 to 53% of cases.

• Classic radiologic findings include air in the biliary tree without previous biliary-enteric anastomosis and reflux of barium into the biliary tree on upper or lower contrast studies.
• In the experience of Safaie-Shirazi and associates, only one third of biliary-enteric fistulas will present with air in the biliary tree.
• ERC
• Ultrasonography
• Intraoperatively, at either open or laparoscopic approach to the gallbladder and liver hilum, it is important that the surgeon recognize the characteristic findings associated with biliary-enteric fistula to avoid injury to the biliary tree.
• In general, adhesions in the right subhepatic area are dense and suggest carcinoma.
• The gallbladder is usually small and fibrotic and adherent to a viscus.
• In such cases, cholangiography through the gallbladder may be invaluable for delineating the anatomy and establishing the diagnosis.
• Transcholecystic cholangiography should be done by direct puncture within a pursestring suture to prevent spill in the case of possible malignancy, and then, if necessary, with a
• Foley catheter, after opening the fundus of the gallbladder and removing stones.
  

Treatment of biliary-enteric fistulas must take into account several factors.

• If the fistula is diagnosed non-operatively, determination must be made as to the
• existence of residual stones,
• whether obstruction is present,
• and the anatomy of the fistula.

Cholecystocolic and cholecystogastric fistulas should be corrected operatively because of the high incidence of cholangitis associated with them.

• Obstruction of the biliary tree must be rectified.
• If there are stones in the common duct, in most cases endoscopic sphincterotomy and stone extraction may be a desirable alternative to operative choledochotomy for stone removal.
• If residual stones are present in the gallbladder or if symptoms are associated with the fistula, it should be approached surgically.
• Although some authors have recommended surgery to avoid complications in the presence of any biliary-enteric fistula, a reasoned approach is that, in the absence of obstruction, residual stones, or symptoms, except for cholecystogastric and cholecystocolic fistulas, no operation should be performed because most fistulas close spontaneously.

In patients with concomitant intestinal obstruction from a passed gallstone, most authors recommend examination of the remaining intestine for additional gallstones before enterotomy or resection and removal of the obstructing stone and any others in the GI tract, but no approach to the biliary-enteric fistula during that operation.

• The advanced age and compromised general health status of most patients with gallstone ileus confer a high surgical risk; decrease of surgery time and complexity at the time of alleviation of the bowel obstruction is desirable.

In the operative approach to the fistula,

• the first considerations are determination of anatomy,
• existence of residual stones in gallbladder and common duct,
• and presence of obstruction.
• These are best determined by intraoperative cholangiogram and may require separate visualization of gallbladder and common duct.
• Meticulous examination of the GI tract should be made for stones.

If a cholecystocolic fistula is diagnosed preoperatively,

• mechanical and antibiotic preparation of the colon should be performed.
• For cholecystocolic fistula,
• choledochotomy is recommended as a first step,
• followed by cholecystectomy, and
• finally takedown and repair of the fistula to reduce bacterial contamination.
• In other cases, the usual approach is repair of the fistula, then cholecystectomy and closure of the bowel.
• Biliary ductal stones must be removed, and any biliary obstruction must be relieved.
• Reports have suggested that, for laparoscopic surgeons skilled in advanced laparoscopic techniques, including duodenal mobilization and intracorporeal suturing and tying, that the laparoscopic approach can be successful in the repair of cholecystoduodenal and cholecystocolic fistulas.
• The principles for the laparoscopic approach to these fistulas are identical to those delineated for the open approach.
  

Choledochoduodenal Fistula

• The choledochoduodenal fistula represents a special category of biliary-enteric fistula because a frequent etiologic mechanism is a posterior or superior duodenal bulb ulcer penetrating into the common bile duct.
• Studies based on ERC suggest that parapapillary choledochoduodenal fistulas are probably more common than peptic ulcer-associated choledochoduodenal fistulas.
• Parapapillary fistulas are caused by common bile duct stones in 96% of the cases and by carcinoma in 4%.
• Gallbladder, bile duct, duodenum, pancreas, and stomach cancer have been found infrequently, and Crohn's disease of the duodenum, paraduodenal abscess, duodenal diverticulum, and ascariasis have been found rarely as etiologic agents.
• The choledochoduodenal fistula caused by peptic ulcer disease occurs between the duodenal bulb and common duct, and the symptoms are those of peptic ulcer disease.
• Symptoms resulting from the fistula are unusual, and cholangitis occurs in less than 10%.
• Air is found in the biliary tree in 14 to 58%, but in up to 100% of cases barium enters the biliary tree through the fistula.
• Exact localization and direct visualization and biopsy should be obtained by endoscopy and ERC.

Recommended treatment of the choledochoduodenal fistula caused by peptic ulcer is treatment of the ulcer.

• There is good evidence that such fistulas heal without sequelae on medical therapy; the risk of biliary stricture exists in the long term after the healing of the fistula.
• Surgery should generally be based on operative indications for the ulcer disease rather than the presence of the fistula, with the tenet that absence of distal bile obstruction and of bile duct stones should be established before any operation.
• If common duct stones, cholangitis, or obstruction coexist with the fistula, the common duct should be approached from above and away from the fistula, and biliary-enteric diversion, when indicated, should be through a Roux-en-Y limb of jejunum.
  

Parapapillary choledochoduodenal fistula was found in 1.2% of a reported series of 1,929 patients treated for biliary tract disease in Japan and was found to be the most common of the internal biliary fistulas in that series, three times as common as cholecystoduodenal fistula. Seventy per cent of patients had abdominal pain, 39% had fever, and 36% had jaundice. Diagnosis at ERCP was by (1) passage of a cannula through the papilla and out through the fistula, (2) visualization of contrast injected into the papilla exiting the fistula, or (3) demonstration that cholangiography was possible through both papilla and fistula.

• Two thirds of patients had no history of previous instrumentation of the biliary tree, although a similar fistula can be caused by mispassage of a bougie at bile duct exploration.
• Two general types of parapapillary fistula have been described.
• One type is small, positioned in the longitudinal fold just orad to the papilla, and corresponding to the intramural portion of the common duct.
• The common duct is only dilated slightly in these cases and invariably contains stones.
• The second type is much larger in size (generally at least 1.5 cm in diameter), is located adjacent to the longitudinal fold, corresponds to the extramural portion of the common duct, and is associated with a markedly dilated common duct.
• Stones were found in the common duct in only 50% of cases of the larger type of fistula.

Treatment for the smaller type of fistula could be as little as endoscopic sphincterotomy to, and possibly to above, the fistula and evacuation of stones, with operative cholecystectomy as indicated. The larger type of fistulas are treated best by operative or lithotripsy evacuation of stones and biliary-enteric anastomosis because of the marked dilatation of the common duct.

Biliobiliary Fistula

• Biliobiliary fistulas make up about 3% of all internal biliary fistulas and result from gallstones.
• They occur between the gallbladder and the common hepatic duct or the pericystic duct region of the common duct.
• These fistulas have acquired the designation of the Mirizzi II syndrome, based on a classification proposed by McSherry and co-workers.
• The most commonly accepted pathologic cause for development of Mirizzi's syndrome is that a gallstone becomes impacted in the ampulla of the gallbladder, and subsequent compression of the common duct by the stone and associated inflammation leads to partial obstruction of the common duct, the Mirizzi I syndrome.
• Continued pressure and inflammation may result in necrosis of the compressed tissue, with development of a fistula between gallbladder and common duct, the Mirizzi II syndrome.
• Corlette and Bismuth have classified these fistulas into type 1,
• with the fistula between the gallbladder ampulla and the common hepatic duct, and
• type 2,
• with a large fistula between the gallbladder and the common duct in the "trajectory of the cystic duct," such that no cystic duct is found.
• Although Corlette and Bismuth indicated that 75% of cholecystobiliary fistulas were type 1, Csendes et al. reported that most such fistulas among 196 patients in their series had type 2 fistulas.
  

In approximately 80% of cases the patients are women, with the average age in the sixth decade.

Symptoms include

• jaundice in 79 to 87% of patients,
• pain in 54 to 96% of patients, and
• fever in 62% of patients.

Diagnosis preoperatively is unusual because there is no specific clinical syndrome, although, when biliobiliary fistula is suspected, ERC should make the diagnosis.

• Most biliobiliary fistulas are discovered intraoperatively and should be suspected when
• markedly dense adhesions are found fusing tissues in the right subhepatic area and
• no plane exists between the main bile duct and the gallbladder.
• Other biliary fistulas may coexist.
• The gallbladder is usually shrunken or may be necrotic, it contains a stone more than 1.5 cm in diameter in 88% of cases, and the common duct contains stones in 68 to 75% of patients with a cholecystobiliary fistula.

In treating such fistulas, Corlette and Bismuth recommended

• initial removal of stones,
• followed by a partial cholecystectomy,
• with a remnant of gallbladder left around the fistula margins to aid in closure of the fistula and associated loss of a part of the circumference of the bile duct wall.
• After exploration of the bile ducts through a choledochotomy distal to and away from the biliobiliary fistula, a T-tube is placed into the bile duct through the fistula, and the gallbladder remnant is closed around the tube.
• Use of gallbladder wall to patch biliary duct defects was also described by Sandblom and colleagues, along with a detailed depiction of the method.
• With large fistulas in which tissue loss is great, Corlette and Bismuth recommended hepatojejunostomy.
• Safaie-Shirazi and associates suggested choledochoduodenostomy for large fistulas, or, alternatively, a patch of the bile duct wall with a vascularized pedicle of gallbladder wall to restore lost tissue.